Bundler clean task

CHANGELOG.md

@@ -1,5 +1,6 @@
 (master)
 
+* Added a `bundle clean` task.  There are no default hooks for it.
 * Use `bundle check` to check if we can skip `bundle install`
 * Run `bundle:install` on rollback (`deploy:reverted`)
 

README.md

@@ -57,6 +57,7 @@ set :bundle_path, -> { shared_path.join('bundle') }             # this is defaul
 set :bundle_without, %w{development test}.join(' ')             # this is default
 set :bundle_flags, '--deployment --quiet'                       # this is default
 set :bundle_env_variables, {}                                   # this is default
+set :bundle_clean_options, ""                                   # this is default. Use "--dry-run" if you just want to know what gems would be deleted, without actually deleting them
 ```
 
 You can parallelize the installation of gems with bundler's jobs feature.
@@ -86,6 +87,13 @@ $ bundle install \
 
 If any option is set to `nil` it will be excluded from the final bundle command.
 
+If you want to clean up gems after a successful deploy, add `after 'deploy:published', 'bundler:clean'` to config/deploy.rb.
+
+Downsides to cleaning:
+
+* If a rollback requires rebuilding a Gem with a large compiled binary component, such as Nokogiri, the rollback will take a while.
+* In rare cases, if a gem that was used in the previously deployed version was yanked, rollback would entirely fail.
+
 ### Environment Variables
 
 The `bundle_env_variables` option can be used to specify any environment variables you want present when running the `bundle` command:

lib/capistrano/tasks/bundler.cap

@@ -19,6 +19,7 @@ namespace :bundler do
           set :bundle_flags, '--deployment --quiet'
           set :bundle_jobs, nil
           set :bundle_env_variables, {}
+          set :bundle_clean_options, ""
     DESC
   task :install do
     on fetch(:bundle_servers) do
@@ -51,6 +52,17 @@ namespace :bundler do
       SSHKit.config.command_map.prefix[command.to_sym].push("bundle exec")
     end
   end
+
+  desc "Remove unused gems intalled by bundler"
+  task :clean do
+    on fetch(:bundle_servers) do
+      within release_path do
+        with fetch(:bundle_env_variables, {}) do
+          execute :bundle, :clean, fetch(:bundle_clean_options, "")
+        end
+      end
+    end
+  end
 end
 
 Capistrano::DSL.stages.each do |stage|